What is the average number of lobes in a human breast?
Which artery passes through the anatomical snuffbox?
Which is the largest nerve that exits the pelvis through the greater sciatic foramen?
Inversion and eversion of foot occurs at which joint
Which of the following statements about the femoral triangle is NOT true?
Which structure is contained within the femoral canal?
Which structure forms the lateral border of the ischiorectal fossa?
Which of the following statements about the lumbrical muscles is correct?
The structure which lies outside the femoral sheath is:
Which artery is primarily responsible for supplying the head and neck of the femur?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 11: What is the average number of lobes in a human breast?
- A. 5
- B. 10
- C. 15 (Correct Answer)
- D. 20
Explanation: ***15*** - Historically, the human breast was described as containing **15 to 20 lobes**, each being a functionally distinct unit for milk production arranged radially around the nipple [1]. - This was the accepted anatomical teaching at the time of this examination. - **Note:** Modern imaging studies (MRI, ultrasound) have since shown that breasts typically contain **7-10 ductal systems/lobes** rather than 15-20, representing an important update to classical anatomy teaching. *5* - This number is too low and does not represent either the classical (15-20) or modern (7-10) understanding of breast lobe anatomy. - Insufficient to account for the complexity of the mammary ductal system. *10* - This represents the **upper range of modern anatomical understanding** (7-10 lobes based on current imaging studies). - While anatomically accurate by today's standards, the classical teaching referenced in this examination specified 15-20 lobes as average. *20* - Represents the **upper limit** of the classical range (15-20 lobes) [1]. - While within the historical normal range, **15 is considered the more typical average** in classical anatomy texts. - Modern research indicates this number significantly overestimates the actual lobe count.
Question 12: Which artery passes through the anatomical snuffbox?
- A. Radial artery (Correct Answer)
- B. Brachial artery
- C. Ulnar artery
- D. Interosseus artery
Explanation: ***Radial artery*** - The **radial artery** is palpable within the **anatomical snuffbox**, as it courses over the scaphoid and trapezium bones towards the deep palmar arch. - This location is clinically significant for feeling the pulse and is vulnerable to injury, especially during **scaphoid fractures**. *Brachial artery* - The **brachial artery** is found in the **arm**, typically running in the cubital fossa, well proximal to the anatomical snuffbox. - It bifurcates into the radial and ulnar arteries at the level of the elbow, not within the wrist structures. *Ulnar artery* - The **ulnar artery** typically lies on the **medial side of the forearm** and wrist, contributing to the superficial palmar arch. - It does not pass through the anatomical snuffbox, which is located on the lateral aspect of the wrist. *Interosseus artery* - The **interosseus arteries** (anterior and posterior) run between the radius and ulna in the forearm, supplying muscles and bones. - These arteries are deep within the forearm compartments and do not traverse the superficial anatomical snuffbox at the wrist.
Question 13: Which is the largest nerve that exits the pelvis through the greater sciatic foramen?
- A. Sciatic nerve (Correct Answer)
- B. Superior gluteal artery
- C. Inferior gluteal artery
- D. Piriformis muscle
Explanation: ***Sciatic nerve*** - The **sciatic nerve** is the largest nerve in the human body, formed from the sacral plexus, and it is indeed the largest structure that passes through the **greater sciatic foramen** as it descends into the posterior thigh. - It supplies motor and sensory innervation to the posterior thigh, lower leg, and foot. *Superior gluteal artery* - The superior gluteal artery exits the pelvis through the **greater sciatic foramen** above the piriformis muscle. - While significant, it is an artery and not a nerve, and it is not the largest structure passing through this foramen. *Inferior gluteal artery* - The inferior gluteal artery also exits the pelvis via the **greater sciatic foramen**, inferior to the piriformis muscle. - Like the superior gluteal artery, it is an arterial structure and not a nerve, and it is not the largest structure in the foramen. *Piriformis muscle* - The **piriformis muscle** originates inside the pelvis and passes through the **greater sciatic foramen** to insert on the greater trochanter of the femur. - Although it occupies a significant portion of the foramen, it is a muscle, not a nerve, and the sciatic nerve is the largest nerve exiting this aperture.
Question 14: Inversion and eversion of foot occurs at which joint
- A. Ankle
- B. Subtalar (Correct Answer)
- C. Tarso-metatarsal
- D. None of the options
Explanation: ***Subtalar*** - The **subtalar joint** (talocalcaneal joint) is primarily responsible for **inversion** and **eversion** movements of the foot. - **Inversion** involves tilting the sole of the foot medially (turning inward), while **eversion** involves tilting the sole laterally (turning outward). - This joint allows the foot to **adapt to uneven surfaces** and plays a crucial role in the biomechanics of walking and running. - The subtalar joint is essential for shock absorption and balance during gait. *Ankle* - The **ankle joint** (talocrural joint) is a hinge joint primarily responsible for **dorsiflexion** and **plantarflexion** of the foot. - It allows moving the foot up and down but has minimal contribution to inversion and eversion. *Tarso-metatarsal* - The **tarso-metatarsal joints** (Lisfranc joints) connect the tarsal bones to the metatarsal bones. - These joints contribute primarily to the **stability and arch integrity** of the foot, with minimal movement capacity. - They allow slight gliding movements but not significant inversion or eversion. *None of the options* - This option is incorrect because the **subtalar joint** is indeed the primary joint responsible for inversion and eversion of the foot. - Understanding foot joint biomechanics is essential for diagnosing gait abnormalities, ankle sprains, and foot pathologies.
Question 15: Which of the following statements about the femoral triangle is NOT true?
- A. Contains the femoral vessels
- B. Floor is formed by adductor longus (Correct Answer)
- C. Lateral margin is formed by sartorius
- D. Medial margin is formed by adductor longus
Explanation: ***Floor is formed by adductor longus*** - The floor of the femoral triangle is actually formed by the **iliopsoas** laterally and the **pectineus** medially. - The **adductor longus** forms part of the medial boundary of the femoral triangle, not its floor. - This is the INCORRECT statement (correct answer for a "NOT true" question). *Contains the femoral vessels* - The femoral triangle is a crucial anatomical space containing the **femoral artery**, **femoral vein**, and **femoral nerve**. - These structures are organized from lateral to medial as nerve, artery, vein (NAVY). *Lateral margin is formed by sartorius* - The **sartorius muscle** forms the lateral boundary of the femoral triangle. - Its medial border defines one of the triangle's sides. *Medial margin is formed by adductor longus* - The **adductor longus** does form the medial boundary of the femoral triangle. - This is anatomically correct along with the inguinal ligament (superior boundary) and sartorius (lateral boundary).
Question 16: Which structure is contained within the femoral canal?
- A. Deep inguinal lymph node (Correct Answer)
- B. Loose areolar tissue and fat
- C. Lymphatic vessels
- D. Femoral vein
Explanation: ***Deep inguinal lymph node*** - The **femoral canal** contains several structures: a **lymph node (of Cloquet or Rosenmüller)**, **lymphatic vessels**, and **loose areolar tissue**. [1] - Among these contents, the **deep inguinal lymph node** (also called the lymph node of Cloquet or Rosenmüller) is the **most clinically significant and specifically named structure**. - This lymph node is an important anatomical landmark, serving as a sentinel node that drains lymph from the lower limb, external genitalia, and perineum. - **Clinically**, it is the structure most commonly referenced when discussing femoral canal contents, particularly in the context of femoral hernias and lymphatic drainage patterns. [1] *Loose areolar tissue and fat* - While **loose areolar tissue and fat** are indeed present within the femoral canal, they are **supporting contents** rather than specifically named anatomical structures. [1] - These tissues fill the space and allow for expansion of adjacent vessels (femoral artery and vein), but they are not the primary structure of anatomical or clinical significance. - When asked about "the structure" in the femoral canal, the named lymph node is the more specific answer. *Lymphatic vessels* - **Lymphatic vessels** do traverse the femoral canal, but they are **conduits** rather than a discrete, named structure. [1] - These vessels drain lymph towards the deep inguinal lymph node (of Cloquet) located within the same canal. - The specifically named lymph node is the more definitive anatomical answer than the unnamed vessels passing through. *Femoral vein* - The **femoral vein** is located in the **intermediate compartment of the femoral sheath**, NOT within the femoral canal. - The femoral sheath has three compartments: lateral (femoral artery), intermediate (femoral vein), and medial (femoral canal). - The femoral vein lies lateral to the femoral canal, making this option clearly incorrect.
Question 17: Which structure forms the lateral border of the ischiorectal fossa?
- A. Perineal membrane
- B. Obturator internus muscle (Correct Answer)
- C. Gluteus maximus
- D. Sacrotuberous ligament
Explanation: ***Obturator internus muscle*** - The **ischiorectal fossa** (also known as the **ischioanal fossa**) is a wedge-shaped space in the perineum, and its lateral wall is formed by the **obturator internus muscle** and its covering fascia [1]. - This muscle originates from the inner surface of the **obturator membrane** and the surrounding bone, descending through the lesser sciatic foramen to insert on the greater trochanter of the femur. *Perineal membrane* - The **perineal membrane** is a dense fibrous sheet that forms the inferior boundary of the **deep perineal pouch**. - It does not form a lateral border of the ischiorectal fossa but rather contributes to the floor of the **urogenital triangle**, anterior to the fossa. *Gluteus maximus* - The **gluteus maximus** is a large muscle of the buttock, primarily involved in extension and lateral rotation of the hip. - It lies superficial to the structures of the perineum and therefore does not form a boundary of the **ischiorectal fossa**. *Sacrotuberous ligament* - The **sacrotuberous ligament** is a strong fibrous band connecting the sacrum to the ischial tuberosity. - While it helps to define the boundaries of the **perineum** posteriorly and contributes to the stability of the **sacroiliac joint**, it does not form the lateral wall of the **ischiorectal fossa**.
Question 18: Which of the following statements about the lumbrical muscles is correct?
- A. All lumbricals are supplied by the median nerve
- B. Flex MCP joints and extend IP joints (Correct Answer)
- C. Origin from the tendons of flexor digitorum superficialis
- D. All lumbricals are supplied by the ulnar nerve
Explanation: Flex MCP joints and extend IP joints - The lumbrical muscles are unique in their attachment, originating from tendons and inserting into the extensor hood, allowing them to perform simultaneous metacarpophalangeal (MCP) joint flexion and interphalangeal (IP) joint extension [1]. - This specific action is crucial for fine motor movements of the fingers, particularly in precision grip. All lumbricals are supplied by the median nerve - This statement is incorrect as only the first and second lumbricals (of the index and middle fingers) are typically supplied by the median nerve. - The third and fourth lumbricals are innervated by the ulnar nerve. All lumbricals are supplied by the ulnar nerve - This statement is incorrect because the first and second lumbricals receive innervation from the median nerve. - Only the third and fourth lumbricals are consistently supplied by the deep branch of the ulnar nerve. Origin from the tendons of flexor digitorum superficialis - This statement is incorrect. The lumbricals originate from the tendons of the flexor digitorum profundus, not the superficialis [1]. - They are unique in that they are the only muscles in the human body that originate from a tendon and insert into a tendon (extensor expansion) [1].
Question 19: The structure which lies outside the femoral sheath is:
- A. Genitofemoral nerve
- B. Femoral vein
- C. Femoral artery
- D. Femoral nerve (Correct Answer)
Explanation: ***Femoral nerve*** - The **femoral nerve** lies lateral to the femoral artery and is therefore situated outside the **femoral sheath**, which encloses the femoral artery, femoral vein, and lymphatic vessels [2]. - It originates from the lumbar plexus (L2-L4) and provides motor innervation to the quadriceps femoris and sensory innervation to the anterior thigh and medial leg. *Femoral artery* - The **femoral artery** is a primary content of the **femoral sheath**, occupying the most lateral compartment. - It is a continuation of the external iliac artery and is a major blood supply to the lower limb. *Femoral vein* - The **femoral vein** lies within the **femoral sheath**, positioned medial to the femoral artery. - It is the primary vein responsible for draining blood from the lower limb and eventually becomes the external iliac vein. *Genitofemoral nerve* - The **genitofemoral nerve** typically emerges on the anterior surface of the psoas major muscle and then usually divides into genital and femoral branches [1]. - While its femoral branch supplies sensory innervation to the skin over the femoral triangle, it does not course within the femoral sheath itself but rather anterior to it or outside its immediate vicinity [1].
Question 20: Which artery is primarily responsible for supplying the head and neck of the femur?
- A. Medial circumflex artery (Correct Answer)
- B. Obturator artery
- C. Lateral circumflex artery
- D. Profunda femoris artery
Explanation: ***Medial circumflex artery*** - The **medial circumflex artery** is the primary blood supply to the **femoral head and neck** in adults. - Its branches, particularly the **retinacular arteries**, ascend along the femoral neck to perfuse the head. *Lateral circumflex artery* - The **lateral circumflex artery** supplies the **vastus lateralis muscle** and contributes to the supply of the **greater trochanter**. - While it anastomoses with the medial circumflex artery, its direct contribution to the femoral head is minimal. *Profunda femoris artery* - The **profunda femoris artery**, or deep femoral artery, is the main arterial supply to the **thigh muscles**. - It gives rise to the medial and lateral circumflex femoral arteries but does not directly supply the femoral head. *Obturator artery* - The **obturator artery** primarily supplies the **adductor muscles** of the thigh and contributes branches to the hip joint capsule. - While it has a small branch (artery to the head of the femur) that may contribute to the femoral head in children, it is not the main source in adults.